Lyell Collection
Geological Society, London, Special Publications
Lyell Centre  |   Lyell Collection  |   Subscriptions   |   Geological Society  |   Email alerts  |   Online bookshop  |   Help

Keywords:
Author:
Advanced search>>
This Article
Right arrow Full Text (PDF)
Right arrow References
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow Request Permissions
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Cowan, G.
Right arrow Articles by Bradney, J.
Right arrow Search for Related Content
GeoRef
Right arrow GeoRef Citation
Geological Society, London, Special Publications; 1997; v. 124; p. 373-386;
DOI: 10.1144/GSL.SP.1997.124.01.22
© 1997 Geological Society of London

Field Studies

Regional diagenetic controls on reservoir properties in the Millom accumulation: implications for field development

Greig Cowan & Joanna Bradney

BG Exploration and Production Ltd, 100 Thames Valley Park Drive, Reading RG6 1PT, UK cowan.g{at}bgep.co.uk

The Millom accumulation comprises two dip-closed culminations situated down-flank of the 1 TCF North Morecambe Field. The depositional environments encountered in the Millom area are similar to those in the North Morecambe area and they share a common depositional layering. However, porosity and permeability are low compared to the Morecambe Fields. Although the presence of permeability reducing platy illite throughout the reservoir can explain the reduced permeabilities in the area, it does not account for the reduced porosity. The abundance of mineral cements (quartz and carbonates) increases rapidly away from the crest of the North Morecambe structure, down-dip towards the Millom area. The migration history of fluids outwards from the deeper parts of the basin is preserved by the cement distributions observed in the Morecambe-Millom area. Porosity in North Morecambe is preserved by an early hydrocarbon charge. The Millom structure had not formed during early hydrocarbon migration and was exposed to mineralizing fluids moving from the Keys Basin to the north. Both structures were filled with the present gas charge during late Cretaceous/early Tertiary gas migration. Poor reservoir properties, especially Kv, renders Millom unsuitable for development by horizontal wells.